The TF-204 4-wire interface is consisting of two units.Each unit has two independent sets of 2-wire / 4-wire connectors.
l Sidetone Adjustment
Unsatisfied sidetone could cause feedback between input and output. In either of these cases, you should minimize the amount of sidetone.
Sidetone Adjustment Procedure:
A) Set Link(5)switch to OFF.
B) Turn the Input Level Reduction Switch(8)to 0dB.
C) Press Test Tone (7) button, a constant beep sound can be heard from the Sidetone(6) Monitoring hole.
D) Adjust Output Level(9) control knob to make the beep level heard properly.
E)Turn the MainSidetone Adjustment M (1) knob by clockwise and anti-clockwise direction slowly. Find minimum listening level.
F) Turn the AuxiliarySidetone Adjustment A (1) knob. Find the minimum listening level.
Repeat this procedure A) to F) for otherchannels.
l Output Level
Output Level Reduction Switch(8)
This switch has 0dB, -20dB and -40dB three levels. It reduces the signal level which is sent to the pin3 and 4 of 4-wire connector (13) atrear panel.
Output Level Adjustment (9)
Thisoutput level adjustment provides a strong average green light on theOutput Level Indicator (10). This occurrence indicates a 0dB line level on 600ohm line. Red light indicates exceeded output level. Occasional transitions to a red light are acceptable.
Output Level Indicator (10)
Green light indicates output level normal.
Red light indicates output level high.
l Input Level
Input Level Reduction Switch(2)
This switch has 0dB and -20dB two levels to match the signal level which is sent from pin1 and 2 of 4-wire connector (13) at rear panel.
Input Level Adjustment (6)
Adjust the Input channel gain to fit different input signal level.This knob provides a strong average green light on theInput Level Indicator (4).Meanwhile the level on pin3 of 2-wire connector is 0dB. Red light indicates exceeded input level. Occasional transitions to a red light are acceptable.
Input Level Indicator (4)
Green light indicates input level normal.
Red light indicates input level high.
Channel A and Channel B are individual to each other when this switch is set to the Off position.
When this switch is set to ON position, Channel A and Channel B are connected.
4-wire In/Out Connector (8)
Input: Pin1 --- Audio+
Pin2 --- Audio- (Common)
Output:Pin3 --- Audio- (Common)
Pin4 --- Audio+
External signal to TF-204 can be balanced or unbalanced. Unbalanced signal is easier to bring in the noise, it is better to bring in balanced signal.
Intercom Line Connector (9)
3-pin XLR female socket
The pinout of the intercom connectors is as follows:
Pin 1 --- Common (Shield)
Pin 2 --- Power (15~30 VDC)
Pin 3 --- Audio
TF-204 adopts 19-inches 1U cabinet, and this workstation can be mounted on rack or placed on desktop. TF-204 uses standard 2-core shield cable. It can be powered by any channel or by A, B (A, B, C, and D) together.
Two XLR-3 connectors for channel A and B are used to connect 2-wire equipments. Pin connector is used to connect 4-wire input and output equipments.
IV Troubleshooting Problem: System feedback (Acoustical)
Cause 1: Input or output signal level is too high
Solution 1: Adjust the signal level
Cause 2: Sidetone of this station or any remote station is not adjusted correctly
Solution 2: Adjust side tonerefer to the procedure in the Front Panel section of this manual.
Cause 3: No terminal in the system.
Solution 3: Check the terminal in the system.
Cause 4: 4-wire equipments connector are not connected well
Solution 4: Check the connection.
Problem: Output level is set to max, the audio level from camera end is still too low
Cause: Output level raw adjustment is not proper
Solution: Set output level raw adjustment to ‘Line’, then adjust output level to proper level
Problem: The audio level heard from camera end is too low
Cause: Input level is too low
Solution: Adjust input level by clockwise to proper level
Problem: Hum or buzz in system
Cause 1: Inductive pickup caused by close proximity of this main station or connected remote stations to power lines or transformers.
Solution 1: Relocate the offending unit.
Cause 2: Intercom line cable is not wired properly; the shield of microphone cable is not connected to Pin-1 of 3-XLR
Solution 2: Check intercom line cable. Make sure all the cables’ Pin-1 of 3-XLR connects correct.
V Technical Specification
300Hz – 4000Hz ±3dB
Balanced, unbalanced self-adaption
Resistance: >10K ohm Bridge
Level: -37dBu-+12dBu (1KHz)
Balanced, unbalanced self-adaption
Resistance: 600 ohm
Level: -43dBu - +8dBu (1KHz)
19” (W) x 1.77” (H) x 6.69” (D), 483mm x 45mm x 170mm